556 Two-Way Pressure Relief Valve
- Diameter: 4 in
- Housing: Aluminum
- Housing Finish: Hard Anodized
- Seals: Neoprene
- Standard Cracking Pressure: 1.00 ± 20% inches of water
Drawing 3D Model
The 556 two-way pressure relief valve is used extensively on military enclosures and provides pressure relief in a variety of scenarios. It protects the enclosure from excess pressure and vacuum during air transport, equalizes pressure due to temperature fluctuations, and relieves back pressure developed when a door is opened and closed.
The 556 can be configured with many pressure settings and with a sealed cover or louvered cover. The most common configurations are shown below.